Press and cage assembly

Claim 1

FOR USE IN A PRESS FOR EXPRESSING FLUID FROM FLUID BEARING MATERIAL INTRODUCED INTO SUCH PRESS, A SCREW SHAFT POSITIONABLE TO EXTEND THROUGH SAID PRESS FROM A MATERIAL INFEED END TO A MATERIAL DISCHARGE END THEREOF, SAID SHAFT HAVING A SUBSTANTIALLY UNIFORM ROOT DIAMETER THROUGHOUT ITS EFFECTIVE LENGTH, SAID SHAFT COMPRISING AT LEAST THREE OPERATIVELY DISCRETE SECTIONS, A PLURALITY OF INTERRUPTED SCREW FLIGHTS ON SAID SHAFT, ONE OF SAID SHAFT SECTIONS HAVING A SCREW FLIGHT PORTION THEREON WHICH IS OF PREDETERMINED UNIFORM CREST DIAMETER AND PITCH, AN ADJACENT ONE OF SAID SHAFT SECTIONS HAVING SCREW FLIGHT PORTIONS THEREON WHICH HAVE PROGRESSIVELY DECREASING CREST DIAMETER AND PITCH RELATIVE TO THE SCREW FLIGHT PORTION OF SAID ONE SECTION, A THIRD OF SAID SHAFT SECTIONS HAVING SCREW FLIGHT PORTIONS THEREON WHICH ARE OF SUBSTANTIALLY UNIFORM CREST DIAMETER AND PITCH WHICH ARE LESS THAN THE CORRESPONDING DIMENSIONS OF THE SCREW FLIGHT PORTIONS ON SAID FIRST AND SECOND MENTIONED SHAFT SECTIONS.